Electrolyzer Standards Update

by Karen Quackenbush, FCHEA

As the national trade association for the fuel cell and hydrogen energy industry, the Fuel Cell and Hydrogen Energy Association (FCHEA) provides regular opportunities to engage industry in developing Regulations, Codes, and Standards (RCS), assess RCS priorities and needs, and identify opportunities to harmonize requirements.

FCHEA’s Technical and Regulatory Working Group (TRWG) has noted the need for robust, harmonized standards for electrolyzers. This article provides the current state-of-play for developing codes and standards relating to electrolyzer technologies.

IEEE is in the process of revising IEEE 1547-2018 - Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces. Grid interconnection falls under the guidance of IEEE 1547-2018 for technical requirements.   Electric Utilities and Regulators rely heavily on these requirements for project specification and approval. Although the scope of this effort isn’t limited to electrolyzer technologies, the new rules will help clarify requirements for the use of electrolyzers in Distributed Energy Resources.

There is also significant work in the international community on developing revised and new requirements for electrolyzers. ISO 22734:2019 - Hydrogen generators using water electrolysis — Industrial, commercial, and residential applications, provides general requirements and test protocols for electrolyzers.

This standard has been adopted in North America as CSA/ANSI B22734:23. National adoptions of ISO 22734 can provide the basis for approval of electrolysis systems.

A revision to ISO 22734: 2019 is in process. This project will provide additional safety requirements specific to dynamic operation, and once complete, would be published as ISO 22734-1: Hydrogen generators using water electrolysis - Part 1: Safety. The scope of this project covers the revision of ISO 22734:2019 in order to establish any additional safety requirements and test methods needed for:

  1. operation of water electrolysis systems coupled with the electricity distribution grid and/or fluctuating and intermittent renewable energy sources (RES) in a dynamic mode.

  2. safety requirements for venting of oxygen

  3. requirements for scale up including electrolyzer systems installed into buildings

  4. other areas, such as:

  • including learnings from other enclosed systems (e.g. HRS) and pre-normative research projects;

  • safety integrated systems;

  • power electronics for connection to the grid; and

  • specific requirements when incorporated into specific applications, e.g. as part of HRS, or hydrogen grid injection system.

Performance requirements for electric grid balancing are to be addressed in the separate ISO TC 197 SC 1 working group developing ISO TR 22734-2 - Hydrogen generators using water electrolysis — Part 2: Testing guidance for performing electricity grid service.

IEC/TC 105 – Fuel Cell Technologies, has also published standards and new activities developing International Standards for fuel cell modules in reverse mode:

  • IEC 62282-8-301:2023 - Fuel cell technologies – Part 8-301: Energy storage systems using fuel cell modules in reverse mode – Power to methane energy systems based on solid oxide cells including reversible operation - Performance test methods, specifies performance test methods of power-to-methane systems based on solid oxide cells (SOCs). Water, CO2, and electricity are supplied to the system to produce methane and oxygen.

  • Test methods for SOC cell/stack assembly units including reversible operation (without any methanation reactor) are already described in IEC 62282-8-101:2020: Fuel cell technologies - Part 8-101: Energy storage systems using fuel cell modules in reverse mode - Test procedures for the performance of solid oxide single cells and stacks, including reversible operation. This document addresses solid oxide cell (SOC) and stack assembly unit(s). It provides for testing systems, instruments and measuring methods to test the performance of SOC cell/stack assembly units for energy storage purposes. It assesses performance in fuel cell mode, in electrolysis mode and/or in reversible operation.

  • IEC 62282-8-102:2019 - Fuel cell technologies - Part 8-102: Energy storage systems using fuel cell modules in reverse mode - Test procedures for the performance of single cells and stacks with proton exchange membrane, including reversible operation

  • IEC 62282-8-201:2020 - Fuel cell technologies - Part 8-201: Energy storage systems using fuel cell modules in reverse mode - Test procedures for the performance of power-to-power systems

Hydrogen quality standards are available based on the end use application

SAE J2719_202003: Hydrogen Fuel Quality for Fuel Cell Vehicles: https://www.sae.org/standards/content/j2719_202003/

ISO 14687:2025: Hydrogen fuel quality — Product specification: https://www.iso.org/standard/82660.html

CGA 5.3 2017: Commodity Specification for Hydrogen: https://blog.ansi.org/2018/01/cga-g-53-2017-commodity-specification-hydrogen/

ASME

ASME published ASME TGP-1-2023: Guidelines to ASME Standards in Hydrogen Value Chains. The intent of this guidance document is to summarize existing standards in hydrogen value chains; and identify relevant standards for specific hydrogen applications. The document is available through ASME here: https://www.asme.org/codes-standards/find-codes-standards/tgp-1-guidelines-asme-standards-hydrogen-value-chains/2023/pdf.

Code Case: ASME has approved a revision to Code Case 3078 for Electrolyzer Cell Stack Assemblies. The Code Case revision is expected to be published very shortly. The Code Case provides rules that may be used to fabricate gasketed electrochemical cell stacks in compliance with Section VIII, Division 1. While Code Cases are not mandatory, compliance may be required by an authority having jurisdiction during the permitting process. Feedback on the Code Case will be considered by ASME as they develop a mandatory language on this subject in a future edition of ASME BPVC Section VIII.

Electrolyzer cell stack assemblies with a maximum allowable working pressure greater than 150 psi, and a cell stack diameter greater than 6 inches fall within the scope of the new rules.

The rules in this Code Case cover the minimum requirements for design, fabrication, assembly, inspection, testing, and documentation of planar geometry gasketed electrochemical cell stacks (ECS) within the Scope described in U-1 for electrolysis.

ASTM #80676 Water quality guidelines for makeup and recirculating waters used in electrolyzers for hydrogen production, is a new activity to develop water quality guidelines for makeup and recirculating waters used in electrolyzers for hydrogen production.  The objective of this working group is to develop a water quality standard guide when operating various types of water electrolyzers to produce hydrogen gas. The guide is expected to provide (i) recommended maximum water impurity levels; (ii) typical methods and systems to purify water that enable conformance and (iii) standard analytical test methods that can be used to validate the conformance. The guide will provide recommendations for limits on both “exogenous” impurities coming from incoming water fed to electrolyzers, and “endogenous” impurities that may be extracted during electrolyzer operation from wetted cell components. Electrolyzer types will include proton exchange, anion exchange, bipolar exchange, solid oxide, and alkaline.

FCHEA will continue to engage in these activities, and work to ensure harmonized requirements to facilitate use of electrolyzer technology systems.

Canadian Standards Association (CSA) C22.2 No. 62282-2-100

by Karen Quackenbush, FCHEA

The CSA FC 62282-2-100 * CSA C22.2 No. 62282-2-100 technical subcommittee has posted the first binational edition of CSA FC 62282-2-100 * CSA C22.2 No. 62282-2- Fuel cell technologies – Part 2-100: Fuel cell stacks and fuel cell modules - (IEC62282-2-100:2020, MOD) for review and comment. This CSA document is the North American adoption of the IEC 62282-2-100 document with deviations. 

National deviations include items such as referencing the appropriate national electrical code and nationally-adopted standards. It also provides important distinctions between requirements for stacks and modules.  The bi-national edition also introduces a new informative annex. This annex provides background material on the classification of Electrochemical Cell Stacks (ECS), used in both electrolyzers and fuel cells, as pressure vessels.

Link to the public review draft: https://publicreview.csa.ca/Home/Details/5618

Comments on the draft binational standard are requested via the CSA Public Review System by June 10, 2025.

Druck Report on the Use and Design of Pressure Sensors for Hydrogen Systems

By Aidan Dennehy, FCHEA

Druck, a UK-based subsidiary of Baker Hughes specializing in pressure measurement, released a report titled Design Considerations for choosing a hydrogen pressure sensor. The report, authored by Senior Product Leader for Industrial Sensors Michael Thomas, provides guidance on the use and design of pressure sensors for hydrogen applications.

Importance of pressure sensors

Given the unique properties and high-pressure storage requirements of hydrogen, accurate and real-time pressure measurement provided by sensors is crucial for the safe operation of hydrogen systems. Beyond safety, pressure sensors ensure that hydrogen systems run as efficiently as possible. The accurate monitoring of hydrogen pressure levels has important implications for preventing permeation and embrittlement and for pressure connection sealings. The hydrogen system’s hazard classification must also be considered.

Permeation and embrittlement

The risk of hydrogen embrittlement (material degradation from hydrogen gas exposure) and hydrogen permeation (movement of hydrogen gas through material) pose unique safety considerations which pressure sensors must account for when being deployed in hydrogen systems. The report found that material such as 316L stainless steel provides some of the best resistance to hydrogen embrittlement, protecting against a potential pressure sensor failure if the embrittlement goes unnoticed. Hydrogen permeation causes damage only when the process pressure falls outside of an acceptable range. Pressure sensors help hydrogen system operators avoid falling outside of that range.

Sealing

Ensuring proper sealing is an important consideration for the safe design and operation of hydrogen systems. System designers should consider how the unique properties and storage requirements of hydrogen impact sealing design choices. The report finds that while certain elastomeric seals may be rated for hydrogen use, metal-to-metal seal connectors are still safer at higher levels of pressure. Proper sealing helps avoid the danger associated with hydrogen leakage.

Hazard classification

The report also highlights the importance of understanding the hazard classification of the operational environment. Given hydrogen’s flammability and explosive potential, sensors must meet the appropriate hazardous area certifications - such as IECeX or NFPA Class I, Div 1 or 2, Group B. System designers should evaluate which, if any, of these certifications are required based on the region and application type.

Center for Hydrogen Safety (CHS) Webinar on Hydrogen Leak Detection

By Aidan Dennehy, FCHEA

On April 17th, the Center for Hydrogen Safety hosted a webinar titled Hydrogen Leak Detection: Technology, Best Practices, and Implementation. The event featured presentations from Rob Early, Technical Manager at the Compressed Gas Association (CGA), and William Buttner, Senior Scientist at the National Renewable Energy Laboratory (NREL). Mr. Early and Mr. Buttner gave a detailed overview of the many considerations required for hydrogen leak prevention and detection.

Goals of leak detection

While not all hydrogen releases are unintentional, accidental leakage can create dangerous situations. Mr Early emphasized that “the best way of dealing with leaks is never to have them at all”. To this end, hydrogen systems must be designed in such a way the risk of leakage is reduced to the smallest possible level. When a leak does occur, processes must be in place to identify its location and estimate its severity. Armed with accurate information, operators can determine the appropriate response so that their system is working safely and efficiently.

The webinar contains information relevant to almost any hydrogen system. Examples of applicability are:

  • Tube trailer fill stations

  • Liquid trailer fill stations

  • Electrolyzer production stations

  • Customer supply systems

  • (liquid or gas storage)
Fuel cell electric vehicle fueling stations

  • HYCO production plants

  • HYCO liquefaction systems

Preventing leaks & associated problems

Mr. Early highlighted four crucial considerations for designing against leakage:

  1. Proper Material & Component Selection: Selecting a material that is well suited for hydrogen and flammable gas service is crucial to preventing leaks. Materials with low melting points, such as copper tubing, should be avoided.

  2. Proper Construction & Fabrication Techniques: After the proper materials & components have been selected, a hydrogen system should be constructed with their end use in mind. For example, welding procedures should be done to avoid even the slightest defect and tested before use.

  3. Minimize Use of Mechanical Connections: The use of routed connections is always preferable if possible. Flanges and other types of mechanical connections should only be used if necessary.

  4. Proper Pressure & Leak Tests at Start-Up: By performing pressure and mechanical integrity tests at the beginning, operators can identify potential failures in their system or detect a leak while it is still nascent.

Hydrogen detectors

If a leak does occur, having an accurate and reliable hydrogen detector is critical. Mr Buttner’s part of the presentation provided an overview of hydrogen detection technologies and strategies.  The presentation outlines several common sensor platforms, including electrochemical (EC), catalytic gas sensors (CGS), thermal conductivity (TC), metal oxide (MOX), and palladium thin film (PTF) types, each with distinct advantages and limitations. While some sensors are highly sensitive or robust, they may be prone to long-term drift, poisoning, or cross-sensitivity. Safety performance depends heavily on matching sensor characteristics to application-specific needs, particularly in high-risk environments like fuel stations, laboratories, and industrial facilities.

A key insight from the presentation is the critical role of sensor placement. Misplaced sensors, even if technically advanced, can fail to detect hydrogen leaks. For example, sensors might not trigger alarms if hydrogen plumes are diverted or diluted before reaching them. This problem can be compounded by the ventilation and HVAC systems. Since point sensors will not detect a leak if the hydrogen does not get to the sensing element, a poor ventilation design may have a negative impact on leak detection. In one simulation, the presence of an HVAC system prevented any detection of a leak at a 0.4% alarm level.

Every hydrogen system has its own set of characteristics and environmental challenges. Differences in parameters such as airflow, background gas composition, and room size can have significant impacts on sensor efficacy. The presentation emphasized the importance of tailoring hydrogen detection strategies to these site-specific parameters. Modeling tools such as CFD (Computational Fluid Dynamics) can enhance safety by informing sensor placement and ventilation design to reduce response times. 

Relevant standards for hydrogen sensors

Mr Buttner also highlighted standards that are relevant to hydrogen sensors. These are:

UL 2075 Standard for Safety Gas and Vapor Detectors and Sensors

  • ISO 26142 (2010) Hydrogen Detector Apparatus-Stationary Applications

  • IEC 60079-29-1:2016 - Explosive atmospheres - Part 29-1: Gas detectors - Performance requirements of detectors for flammable gases

  • ASME B31.12 Hydrogen Piping and Pipelines

  • I 60079-10-2020: Explosive atmospheres - Part 10-1: Classification of areas – Explosive Gas Atmospheres

  • NFPA 2: Hydrogen Technologies Code

  • NFPA 70 National Electric Code

To access a recording of the webinar or to learn more about the Center for Hydrogen Safety, click here.

Drager Report on Hydrogen Risk Management for Production Plants

By Aidan Dennehy, FCHEA

Drager is a German engineering company and manufacturer of medical and safety technology products. The firm released a report on risk management strategies at hydrogen production plants. The complex nature of these plants, which often feature compressor facilities, production processes, and transportation pipelines, among other sensitive technologies, requires a careful re-evaluation of hydrogen-related risks and safety practices. Drager’s report provides guidance on how to assess, prioritize, and respond to these risks.

Overview of hydrogen safety challenges

Hydrogen's distinctive properties make it an appealing energy source, but they also introduce specific safety challenges. The report discusses hydrogen’s low density, tiny molecular size, high flammability, lack of odor, invisible flames, and ability to interfere with carbon monoxide alarms.

·       Low density: Hydrogen is a very light gas (roughly 14 times lighter than air) and disperses quickly when released, thus making detecting leaks difficult. Hydrogen sensors should be installed strategically in a building, with special attention paid to the ceiling. Computational fluid dynamics modeling can help designers predict where hydrogen may go in the event of a leak.

·       Tiny size: Hydrogen molecules are small and can easily permeate materials, causing them damage and potentially leading to a leak. The appropriate selection, handling, and maintenance of all materials used while working with hydrogen is crucial for preventing and addressing permeation.

·       High flammability: Hydrogen requires very low energy to ignite (roughly 4 times less than gasoline) and has a wider flammability range than other fuels. Even the static shock caused by friction between the gas and the leak surface could cause ignition. Special consideration is required to reduce the possibility of ignition, such as by avoiding the use of certain equipment nearby and preventing/detecting leaks.

·       Invisible flames: If ignition does occur, hydrogen flames are nearly impossible to see with the naked eye during the day and extremely pale at night. Special flame detectors should be used so that an ignition does not go unnoticed.

·       Lack of odor: Another reason why it is difficult to detect the presence of hydrogen is the lack of odor. While a sulfurous odorant artificially introduces a scent to natural gas and propane, there is currently no known odorant light enough to be compatible with hydrogen.

·       Interference: In some applications, carbon monoxide (CO) alarms are sensitive to hydrogen, which can cause false alarms to occur. To prevent this, hydrogen-compensated CO sensors should be used instead.

Hierarchy of risk management

A well-developed safety strategy is focused on preventing hazardous events before they occur but is prepared to mitigate them if prevention is not possible. The report outlines a “hierarchy of controls”, which prioritizes controls for safety strategies from most to least effective: elimination, substitution, engineering controls, administrative controls, and PPE.

1.       Elimination: The priority should be to physically remove the hazard. By eliminating safety risks, such as unnecessary electrical components, the hazard is mitigated most effectively.

2.       Substitution: In the event the hazardous material or process is essential, replace it with a less hazardous alternative. This reduces risk by removing the original danger and replacing it with something safer.

3.       Engineering: Utilize engineered solutions that reduce exposure to hazards without relying on worker behavior. Examples include explosion-proof electrical equipment, plant fire protection, and ventilation equipment.

4.       Administrative: This type of control changes the way people work by implementing policies, procedures, and training to minimize exposure to hazards. Examples include a safety matrix, emergency and hazard prevention management, and defining permitted activities.

5.       Personal Protective Equipment (PPE): The least effective, but still important, control is outfitting workers with PPE to protect them from leaks, explosions, and fires. Examples include mobile gas detection, ESD safety shoes, and thermal imaging cameras.

As demand for hydrogen grows, new market participants will have to familiarize themselves with these risks and develop their own strategies for mitigating them. To read the full report from Drager on hydrogen risk management at production plants, click here.

New Portable Hydrogen Detection Method Highlights Recent Progress

By Aidan Dennehy, FCHEA

Researchers at the University of South Florida (USF) have developed a new portable method for detecting very low concentrations of hydrogen outdoors. Dr Andrea Muller, Associate Professor of Physics at USF, and Mr Charuka Arachchige, PhD student at USF, published their results in the peer-reviewed journal Applied Optics. The development speaks to recent progress in the efficacy of hydrogen sensors in challenging conditions, crucial for the safe and efficient use of hydrogen.

A Raman analyzer (also known as Raman spectroscopy) is a method of chemical analysis that identifies and quantifies substances by scattering light and analyzing what’s reflected. While Raman analyzers which detect liquids and solids are commercially available, gasses, especially in low concentration, are particularly challenging for this type of instrument to detect. Dr Muller and Mr. Arachchige developed a new method that enhances the scattering signal with multiphases cavity enhancement, a type of enhancement that allows for disturbances and does not require specialized lasers. A valuable aspect of the new instrument is that it works outdoors, a particularly challenging space for hydrogen sensors given the fast speed at which the gas disperses. Dr Muller explained, “Our new Raman analyzer can handle outdoor environments and map out minute hydrogen concentration changes around a source with reasonable form factor and power consumption,”. The instrument was able to detect excess hydrogen levels as low as 63 parts per billion in outdoor settings from several meters away.

Dr Muller expressed his hope that his portable Raman analyzer could contribute to various initiatives, saying “Our versatile instruments could be useful in a variety of industrial and scientific applications, including exploration of the significant hydrogen resources that exist beneath the Earth's surface,”.

The hydrogen detection space is constantly innovating and developing new technologies that improve the safety and efficiency of hydrogen applications. Each application is different and can vary widely from one to the next. These differences have unique implications needs which technologies such as portable Raman analyzers can address.

To read the full press release from Applied Optics, click here.